Re: [Xen-devel] HPET enabled in BIOS, not presented as available_clocksource -- config, kernel code, &/or BIOS?

From: PGNet Dev
Date: Sat May 13 2017 - 19:18:05 EST


On 5/13/17 3:15 PM, Valentin Vidic wrote:
> Try booting without 'hpet=force,verbose clocksource=hpet' and it should
> select xen by default:

Nope. Well, not quite ...

With both

'hpet=force,verbose clocksource=hpet'

removed, I end up with

cat /sys/devices/system/clocksource/clocksource0/available_clocksource
tsc xen
cat /sys/devices/system/clocksource/clocksource0/current_clocksource
tsc

But with

clocksource=xen

*explicitly* added

cat /sys/devices/system/clocksource/clocksource0/available_clocksource
tsc xen
cat /sys/devices/system/clocksource/clocksource0/current_clocksourcexen
xen

and in *console*, NOT dmesg, output,

grep -i hpet tmp.txt
(XEN) ACPI: HPET 9E8298F8, 0038 (r1 SUPERM SMCI--MB 1072009 AMI. 5)
(XEN) ACPI: HPET id: 0x8086a701 base: 0xfed00000
(XEN) [VT-D] MSI HPET: 0000:f0:0f.0
(XEN) Platform timer is 14.318MHz HPET
[ 0.000000] ACPI: HPET 0x000000009E8298F8 000038 (v01 SUPERM SMCI--MB 01072009 AMI. 000000
[ 0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[ 0.000000] ACPI: HPET 0x000000009E8298F8 000038 (v01 SUPERM SMCI--MB 01072009 AMI. 000000
[ 0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[ 8.515245] hpet_acpi_add: no address or irqs in _CRS
[ 8.515245] hpet_acpi_add: no address or irqs in _CRS
(XEN) [2017-05-13 23:04:27] HVM1 save: HPET



and

dmesg | grep -i clocksource | grep -v line:
[ 0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns
[ 0.004000] clocksource: xen: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns
[ 0.375709] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[ 4.656634] clocksource: Switched to clocksource xen
[ 8.912897] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x2c94dffea94, max_idle_ns: 440795361700 ns

jiffies, now? hm. no idea where that came from. and why the 'tsc' ?

So I'm still unclear -- is this^ now, correctly "all" using MSI/HPET?